diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 6374c1ea9..a6924bf23 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -1814,7 +1814,7 @@ class SerializerMethodField(Field):
 
     For example:
 
-    class ExampleSerializer(self):
+    class ExampleSerializer(Serializer):
         extra_info = SerializerMethodField()
 
         def get_extra_info(self, obj):